diff --git a/README.md b/README.md
index 6d71df453049a89ceae276c2aee20b59d508a760..33bced237433c1bbb58cdb5c895013bc0b7f8b4f 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,9 @@ $ sudo apt install ./ttk-1.1.0-ubuntu-22.04.deb
 ## Modifications à apporter à la librairie
 
 Ces modifications doivent être faites sur les fichiers situés dans `usr/include/ttk/vtk/`.  
+
+### Modifications d'en-têtes
+
 Dans le fichier d'en-tête **ttkContourForests.h**, modifier les lignes 54 à 56 pour remplacer les guillemets par des chevrons :
 
 ```
@@ -46,10 +49,189 @@ Se rendre ensuite dans le fichier d'en-tête **ttkFTRGraph.h** et modifier les l
 #include <ttkFTRGraphStructures.h>
 ```
 
+### Fichiers à ajouter
+
 <details>
-  <summary markdown="span">Enfin, créer le fichier **ttkFTRGraph.h** :</summary>
+  <summary markdown="span">Créer le fichier <b>ttkFTRGraphStructures.h</b> :</summary>
+
+  ```c++
+  #pragma once
+
+  #include <vtkCellData.h>
+  #include <vtkCharArray.h>
+  #include <vtkDataSet.h>
+  #include <vtkDoubleArray.h>
+  #include <vtkIntArray.h>
+  #include <vtkNew.h>
+  #include <vtkPointData.h>
+  #include <vtkUnsignedCharArray.h>
+  #include <vtkUnstructuredGrid.h>
+
+  #include <FTRCommon.h>
+  #include <FTRDataTypes.h>
+  #include <Graph.h>
 
+  namespace ttk {
+    namespace ftr {
+
+      /// Vertex / Node / Arc data inherit from this
+      /// master structure.
+      struct ObjectData {
+        inline void allocArray(vtkDataArray *const arr,
+                              const char *fieldName,
+                              size_t nbElmnt) {
+          arr->SetName(fieldName);
+          arr->SetNumberOfComponents(1);
+          arr->SetNumberOfTuples(nbElmnt);
+
+  #ifndef TTK_ENABLE_KAMIKAZE
+          if(!arr) {
+            Debug dbg{};
+            dbg.setDebugMsgPrefix("FTRGraph");
+            dbg.printErr("unable to allocate " + std::string{fieldName}
+                        + " the program will likely crash");
+          }
+  #endif
+        }
+      };
+
+      struct NodeData : public ObjectData {
+        vtkNew<vtkIntArray> ids{};
+        vtkNew<vtkIntArray> types{};
+        vtkNew<vtkDoubleArray> scalars{};
+
+        explicit NodeData(const ttk::ftr::idVertex nbNodes) {
+          allocArray(ids, "VertexId", nbNodes);
+          allocArray(types, "CriticalType", nbNodes);
+          allocArray(scalars, "Scalar", nbNodes);
+        }
+
+        void addNode(const ttk::ftr::Graph &graph,
+                    const ttk::ftr::idNode n,
+                    const double scalar) {
+          ids->SetTuple1(n, graph.getNode(n).getVertexIdentifier());
+          types->SetTuple1(n, (double)graph.getNode(n).getType());
+          scalars->SetTuple1(n, scalar);
+        }
+
+        void addArrays(vtkPointData *pointData,
+                      ttk::ftr::Params ttkNotUsed(params)) {
+          pointData->AddArray(ids);
+          pointData->SetScalars(types);
+          pointData->AddArray(scalars);
+        }
+      };
+
+      struct ArcData : public ObjectData {
+        vtkNew<vtkIntArray> ids{};
+        vtkNew<vtkCharArray> reg{};
+  #ifndef NDEBUG
+        vtkNew<vtkUnsignedCharArray> fromUp{};
+  #endif
+        std::map<ttk::ftr::idVertex, vtkIdType> points;
+
+        ArcData(const ttk::ftr::idSuperArc nbArcs) {
+          allocArray(ids, "ArcId", nbArcs);
+          allocArray(reg, ttk::MaskScalarFieldName, nbArcs * 2);
+  #ifndef NDEBUG
+          allocArray(fromUp, "growUp", nbArcs);
+  #endif
+        }
+
+        void setPointInfo(const ttk::ftr::Graph &ttkNotUsed(graph),
+                          const ttk::ftr::idSuperArc ttkNotUsed(a),
+                          const vtkIdType skeletonVert,
+                          bool r = false) {
+          reg->SetTuple1(skeletonVert, r);
+        }
+
+        void setArcInfo(const ttk::ftr::Graph &graph,
+                        const ttk::ftr::idSuperArc a,
+                        const vtkIdType skeletonCell) {
+          ids->SetTuple1(skeletonCell, a);
+  #ifndef NDEBUG
+          fromUp->SetTuple1(skeletonCell, graph.getArc(a).getFromUp());
+  #else
+          TTK_FORCE_USE(graph);
+  #endif
+        }
+
+        void addArrays(vtkUnstructuredGrid *arcs,
+                      ttk::ftr::Params ttkNotUsed(params)) {
+          // original size may be too large
+          ids->SetNumberOfTuples(arcs->GetNumberOfCells());
+          arcs->GetCellData()->SetScalars(ids);
+          reg->SetNumberOfTuples(arcs->GetNumberOfPoints());
+          arcs->GetPointData()->AddArray(reg);
+  #ifndef NDEBUG
+          fromUp->SetNumberOfTuples(arcs->GetNumberOfCells());
+          arcs->GetCellData()->AddArray(fromUp);
+  #endif
+        }
+      };
+
+      struct VertData : public ObjectData {
+        vtkNew<vtkIntArray> ids{};
+        vtkNew<vtkIntArray> regionType{};
+  #ifdef TTK_ENABLE_FTR_VERT_STATS
+        vtkNew<vtkIntArray> touch{};
+        vtkNew<vtkIntArray> arcActif{};
+        vtkNew<vtkIntArray> taskActif{};
+  #endif
+
+        explicit VertData(const ttk::ftr::idVertex nbVertices) {
+          allocArray(ids, "ArcId", nbVertices);
+          allocArray(regionType, "RegionType", nbVertices);
+  #ifdef TTK_ENABLE_FTR_VERT_STATS
+          allocArray(touch, "Visit", nbVertices);
+          allocArray(arcActif, "Arc active", nbVertices);
+  #endif
+        }
+
+        void setVertexInfo(const ttk::ftr::Graph &graph,
+                          const ttk::ftr::idVertex v) {
+
+          if(!graph.isVisited(v)) {
+            // Problem, we should have visited all vertices
+            // return to avoid crash
+            return;
+          }
+
+          const ttk::ftr::idSuperArc curArcId = graph.getArcId(v);
+          ids->SetTuple1(v, curArcId);
+
+          int downNodeType
+            = (int)graph.getNode(graph.getArc(curArcId).getDownNodeId())
+                .getType();
+          regionType->SetTuple1(v, downNodeType);
+
+  #ifdef TTK_ENABLE_FTR_VERT_STATS
+          touch->SetTuple1(v, graph.getNbTouch(v));
+          arcActif->SetTuple1(v, graph.getNbArcActive(v));
+  #endif
+        }
+
+        void addArrays(vtkDataSet *segmentation,
+                      ttk::ftr::Params ttkNotUsed(params)) {
+          segmentation->GetPointData()->AddArray(ids);
+          segmentation->GetPointData()->SetActiveScalars(ids->GetName());
+          segmentation->GetPointData()->AddArray(regionType);
+  #ifdef TTK_ENABLE_FTR_VERT_STATS
+          segmentation->GetPointData()->AddArray(touch);
+          segmentation->GetPointData()->AddArray(arcActif);
+  #endif
+        }
+      };
+    }; // namespace ftr
+  }; // namespace ttk
   ```
+
+</details>
+
+<details>
+  <summary markdown="span">Enfin, créer le fichier <b>ttkFTRGraph.h</b> :</summary>
+
+  ```c++
   /// \ingroup vtk
   /// \class ttkFTRGraph
   /// \author Charles Gueunet <charles.gueunet@kitware.com>